The overall objective of the proposed research is an understanding of the molecular mechanisms involved in two fundamental processes of biological energy transduction which take place in the plasma membrane of Neurospora. Specifically, we hope to gain information which will contribute to an understanding of the molecular mechanism by which the Neurospora plasma membrane ATPase generates a membrane potential and the molecular mechanism by which the glucose carrier responds to the membrane potential to catalyze the active transport of glucose across the plasma membrane. With respect to the electrogenic ATPase, we plan to a) fully quantitate the phenomenon of ATP hydrolysis-dependent generation of a transmembrane electrical potential, b) investigate several aspects of the catalytic mechanism, and c) identify, isolate, and reconstitute the enzyme in a defined vesicle system. With respect to the glucose carrier we plan to a) develop a reliable assay for glucose carrier function in Neurospora plasma membrane vesicle and b) identify, isolate, and reconstitute the glucose carrier in a defined vesicle system.